What is Line: Definition and 1000 Discussions

Líně is a municipality and village in Plzeň-North District in the Plzeň Region of the Czech Republic. It has about 2,800 inhabitants. Líně lies approximately 11 kilometres (7 mi) south-west of Plzeň and 95 km (59 mi) south-west of Prague.

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  1. A

    Calculating the reactive power of a transmission line

    I have a single machine connected to an infinite bus with the following parameters: - Sending end power = 3.75MW - RL=5.18 ohms - XL=130 ohms - VS (Generator bus)=161kV - VR (Infinite bus)=161kV - Sending end voltage angle (delta) = 0.01877 (Angle which allows 3.75MW to be transferred)...
  2. P

    Electric Field of Linear Charge along a Line Segment

    Homework Statement Consider a straight line segment of 3L and with a linear charge density λ. Determine the electric field, E, of at point P, which is a point within the segment and along the axis. (figure attached) Homework Equations dE=kdQ/r^2 The Attempt at a Solution I attempted solving...
  3. C

    I What is the hyper-cylindrical line element?

    What is the hyper-cylindrical line element?
  4. M

    MHB Can you find the slope of a line passing through two points with this formula?

    Show that the slope of the line passing through the two points (x, x^2) and (x + h, (x + h)^2) is 2x + h. Let me see if I can solve this baby on my own. Let m = slope = 2x + h m = [(x + h)^2 - x^2]/[(x + h) - x] If I simplify the right side, it should give me m, right? At the very end, I...
  5. J

    I Lorentzian line shape integration

    Hi, I know this might be a bit dum but I'm currently stuck with this integral. In this link: http://www.pci.tu-bs.de/aggericke/PC4e/Kap_III/Linienbreite.htm I know he's doing the right thing, but I really don't understand the integral of a(omega). How come it is E(1/(i(ω-ω0) -γ) -...
  6. M

    MHB What are the intervals on the number line for |x| < 2 and |x| > 0?

    The set of real numbers satisfying the given inequality is one or more intervals on the number line. Show each interval on the number line. 1. | x | < 2 Solution: -2 < x < 2 This can be written as (-2, 2). ----(-2-----0----2)---- Correct? 2. | x | > 0 Solution: The point x lies to the...
  7. L

    MHB Finding a parameter for which a line is orthogonal to a curve

    Hiya again, I am trying to solve this problem, I thought I got somewhere, but kinda stuck. The graph of y^2=x^3 is called a semicubical parabola. Determine the constant b so that the line y = -(1/3)x+b meets this graph orthogonally. I found the derivative of the curve by using implicit...
  8. R

    Line integral of vector field from Apostol calculus

    Homework Statement Here are the three problems that i couldn't solve from the book Calculus volume 2 by apostol 10.9 Exercise 2. Find the amount of work done by the force f(x,y)=(x^2-y^2)i+2xyj in moving a particle (in a counter clockwise direction) once around the square bounded by the...
  9. Bunny-chan

    Distance between point coordinates in a straight line

    Homework Statement Let A = (1,2,5) and B = (0,1,0). Determine a point P of the line AB such that ||\vec{PB}|| = 3||\vec{PA}||. Homework EquationsThe Attempt at a Solution Initially, writing the line in parametric form\vec{AB} = B - A = (0-1,1-2,0-5) = (-1,-1,-5)\\ \\ \Rightarrow \vec{v} =...
  10. kolleamm

    B Find line slope based on degrees (for video game programming)

    I'm trying to code a script for a character in my game. This will tell the character if the player is in front or behind them. Basically I know the coordinates of the character and their angle of rotation (if rotated 45 deg, that is where they are looking) Perpendicular to their angle is a...
  11. P

    MHB Luca's question via email about a line integral....

    I am assuming that this line integral is along the straight line from $\displaystyle \begin{align*} (0,0,0) \end{align*}$ to $\displaystyle \begin{align*} \left( 5, \frac{1}{2}, \frac{\pi}{2} \right) \end{align*}$, which has equation $\displaystyle \begin{align*} \left( x, y, z \right) = t\left(...
  12. G

    Transmission line impedance etc

    All transmission lines have a characteristic impedance which is different based on their length and voltage and frequency (for AC lines) , Also all transformers and their primaries have a different impedance based on the turnsratio, core steel type etc factors. Now I read that for any given line...
  13. R

    Line integral problems in Apostol calculus

    Homework Statement A two dimensional force field f is give by the equation f(x,y)=cxyi+x^6 y^2j, where c is a positive constant. This force acts on a particle which must move from (0,0) to the line x=1 along a curve of the form y=ax^b where a>0 and b>0 Homework Equations Find a value of a(in...
  14. F

    How can I use the expression for a in this problem

    Homework Statement A random sample of size ##n## from a bivariate distribution is denoted by ##(x_r,y_r), r=1,2,3,...,n##. Show that if the regression line of ##y## on ##x## passes through the origin of its scatter diagram then[/B] $$\bar y \sum^n_{r=1} x_r^2=\bar x\sum^n_{r=1} x_r y_r$$ where...
  15. M

    MHB But since distance is always positive, can we say that | a - b | = | b - a |?

    On page 9 of my David Cohen Precalculus textbook (3rd Edition), the following property is given: The distance between a and b is | a - b | = | b - a |. Question: Can we say that | a - b | = | b - a | because distance is always positive? Note: a and b are real numbers.
  16. B

    Potential due to a line charge

    Homework Statement A line charge with uniform charge distribution and linear charge density ##\lambda## lie along z-axis from ##(0,0,-d)## to ##(0,0,+d)##. Find electric field due to this charge along z, x-axis and potential at ##(0,0,2d)##, ##(\sqrt{3}d, 0,0)## and ##(3d/2, 0 , d)##...
  17. P

    Solving Plane Pressure Problem: Finding the Line of Action

    Homework Statement I am trying to study for an exam and a section in the book on pressure on a plane is shown in the attached picture. I am trying to understand how equation15.16 was derived. I know normally the line of action is found using moments so this seems to be a short cut but I...
  18. O

    Can Power Lines Transmit Radio Signals in Emergencies?

    Our street electric power lines have frequency of 50 Hz or 60 Hz.. what would happen if you increase the frequency higher to radio frequencies or microwaves.. would current still flow? and can you make it as antenna for emergency transmission?
  19. R

    I Confusion regarding line integrals

    Sorry if this is the wrong place to post this, but I wasn't sure where exactly to put it. When we calculate the force on a closed loop of current-carrying wire in a uniform magnetic field, We calculate the line integral of the loop to be 0. However, when we evaluate the line integral for an...
  20. M

    Saturation line for a given substance

    "The saturation line for a given substance is the combination of temperature and pressure where 100% vapor exists. At any point below this line, there will be a mixture of vapor and liquid, until a point is reached when only the liquid phase exists." I don't understand above passage from...
  21. K

    Integral of a area under a straight line as summation

    Homework Statement Homework Equations Summs: $$1+2+3+...+n=\frac{n(n+1)}{2}$$ $$1^2+2^2+3^2+...+n^2=\frac{n(n+1)(2n+1)}{6}$$ The Attempt at a Solution $$\Delta x=\frac{b}{n}$$ $$S_n=f\left( \frac{\Delta x}{2} \right)\Delta x+f\left( \Delta x+\frac{\Delta x}{2} \right)\Delta x+...+f\left(...
  22. A

    Find the equation of the plane given point and line (3D)

    ∴1. Homework Statement Find an equation for the plane that contains the point (1,-1,2) and the line x=t, y=t+1, z=-3+2t? 2. Homework Equations The Attempt at a Solution I don't know what I am doing wrong but everytime I try to do these plane questions my amswer is always the opposite sign of...
  23. W

    Get vibration frequency form absorption spectra line

    Homework Statement [/B] "Absorption spectra of gaeous HCl show a line at 3.5 μm which results form molecular vibration (oscillation from interatomic distance)" How do I get the frequency of vibration from this? Homework Equations ? If I knew this, then I could probably solve the problem The...
  24. Z

    Reflection of triangle over a line

    Homework Statement How to rotate a triangle over a line? I have provided a attachment for it? Homework Equations Y= mx +c I don't know the eq for reflection The Attempt at a Solution My plan is find the eq of line. I have got points for the end points of the line but i don't know how to...
  25. H

    Troubleshooting Analog Delay Line Simulation in Multisim

    I'm trying to construct an analog delay (series of low pass filters) and demonstrate the properties of a transmission line (reflection, attenuating etc.) using a multisim simulation (my attempt attached below). But on the oscilloscope I don't get any kind of reflection. What should I do...
  26. Z

    Java Draw circles at end Point of Line with End Points as Centre

    Hi, I am trying to draw circles at the end points of a line but circle centre is not exactly on the end point of the line. Can somebody please guide me. import java.applet.Applet; import java.awt.*; import javax.swing.*; public class JCircle extends Applet{ int x1=30; int y1=30...
  27. Arij

    Other Email Request: Join Research Group?

    I am sorry if this sounds very basic, but I am really troubled on what to title an email regarding a request to join a research group! Any ideas or guidelines?
  28. M

    A Time differentiation of fluid line integrals

    I am looking at a proof from a book in fluid dynamics on time differentiation of fluid line integrals - Basically I am looking at the second term on the RHS in this equation $$ d/dt \int_L dr.A = \int_L dr. \partial A / \partial t + d/dt \int_L dr.A$$ The author has a field vector A for a...
  29. Toby_phys

    Line Integrals around a Square on the x-y Plane

    Homework Statement Evaluate the following line integrals, showing your working. The path of integration in each case is anticlockwise around the four sides of the square OABC in the x−y plane whose edges are aligned with the coordinate axes. The length of each side of the square is a and one...
  30. X

    N-body simulation - straight line orbits

    Homework Statement The problem is your typical N-body simulation, implemented using Python and Numpy. The implementation specifically calls for using the Euler-Cromer method. For this particular case I used the Sun and the first 4 planets of the solar system. Essentially the problem is I'm...
  31. Nikhil N

    How to choose an amplifier to couple the noise into data line

    Hii... I have to couple the noise into a communication cable for analyzing the performance of the communication. I am using a function generator which will generate a white noise of 1-2V(rms) and I have a current transformer to couple this to the communication line. The current transformer has...
  32. bubblescript

    Find line tangent to curve which is parallel to other line

    Homework Statement Find the line tangent to the curve f(x)=0.5x2+3x-1 which is parallel to the line g(x)=x/2+0.5 Homework Equations f'(x)=x+3 The Attempt at a Solution I know it involves taking the derivative of f(x) and using it somehow, but I don't know where to go from there.
  33. frostysh

    Hyperbola and the Line in the Cartesian coords.

    Homework Statement We have the hyperbola, the focal stuff of which is on the Abscissa axis. $$x^2 - 2y^2 = 4 $$, and we have a line $$3x - 4y = 2$$, and we need to understand if this two crazy stuff will intersect, or be tangent, or nothing like the previous one. Homework Equations I don't...
  34. I

    Values of c for which quartic curve intersects a line

    Homework Statement For what values of c is there a straight line that intersects the curve ##y = x^4+c x^3+12x^2-5x+2## in four distinct points ? Homework Equations Concept of concavity, Vieta's formulas (link) The Attempt at a Solution Suppose a straight line ##y = mx+b## intersects this...
  35. M

    MHB Number Line & Intervals (Part 2)

    The set of real numbers satisfying the given inequality is one or more intervals on the number line. Show the intervals on a number line. (A) |x - 4| < 4 (B) |x + 5| >= 2 For (A), I did the following: -4 < x - 4 < 4 I now add 4 to each term. 0 < x < 8 On the number line, I would need to...
  36. M

    MHB Number Line & Intervals (Part 1)

    The set of real numbers satisfying the given inequality is one or more intervals on the number line. Show the intervals on a number line. (A) |x| < 2 (B) |x| > 0 For (A), I must plot -2 < x < 2 on the number line. In interval notation it is written (-2, 2). Is this right? For (B), we have...
  37. M

    MHB Approximate Location On Number Line

    Show the approximate location of the irrational number [(3 - sqrt{5})/2]^(1/2) on a number line without a calculator. Then use a calculator to confirm your approximation. I can find the approximate location using a calculator. How is this done without a calculator?
  38. louisnach

    Electrical Engineering, power system, transmission line

    Homework Statement A 400 kV transmission line has a length of 500 km and a reactance of 0,4 Ω/km. How much power can you transmit, if the power angle (the angle between the voltages of the beginning and the end) is limited to 25 degrees? What would then be the line’s boundary power limit for...
  39. E

    Expert Tips for Zip Line Anchoring | How to Secure Your Backyard Zip Line

    So I'm making an ~200ft long zip line with the top being anchored to a tall tree in my backyard. My problem is I need an anchor for the bottom. Can I use a 6"x6"x12' plywood buried 4 feet in the ground with a guy wire anchored to a 4"x4"x4' 2.5 feet into the ground? What would you say I should...
  40. 8

    MHB ACT Problem: Finding x-intercept Of LIne Given 2 Points

    What is the x-intercept of the line that passes through points (-3,7) and (6,4) in the standard (x,y) coordinate plane?
  41. DaTario

    I How to obtain the inverse (reciprocal) of a line segment?

    Hi All, Which are the ways one can geometrically obtain, given a line segment AB with length x and an unitary segment OC, a line segment with length 1/x ? Straight edge and compass are allowed (also some auxilliary curve). Best wishes, DaTario
  42. mesa

    B What is the vacuum at the Karman line?

    Hey guys, what is the vacuum at the Karman line (100km straight up). I found conflicting sources on this. Wikipedia links to a calculator that states it is ~2.4*10^(-4)T, while another chart I found says it is in between 1.09 and .0075 Torr...
  43. L

    Schutz GR Book, Question about World line.

    This isn't homework, nor is it an exercise problem; merely a question about a diagram. Re: B.Schutz book "A First Course in General Relativity" 2nd Edition, (Asian print version), page 5, Figure 1.1 "A spacetime diagram in natural units". From section 1.4 Spacetime diagrams: A world line is...
  44. Schaus

    Find the equation of the tangent line of the curve

    Homework Statement Find the equation of the tangent line to the curve ##\ xy^2 + \frac 2 y = 4## at the point (2,1). Answer says ##\ y-1 = -\frac 1 2(x-2)## And with implicit differentiation I should have gotten ##\frac {dy} {dx}= -\frac {y^2} {2xy-\frac {2} {y^2}}## Homework Equations ##\...
  45. Rodolfo

    Engineering Book that covers transfer function of transmission line?

    I've been looking for that in various applied electromagnetics books but none of them cover that subject even on the internet the only website I saw it mentioned was in this forum I guess I'd like a book with a level a little above for example cheng or balanis
  46. F

    A About the nodal line in defining Euler angles

    I hope someone can explain this to me. In the definition of Euler angles, the body-fixed-azimuthal angel γ is measured from the nodal line that defines the intersection of the body-fixed-XY plane and the space fixed-xy plane to the body-fixed-Y axis. This is the green line in this image from...
  47. BvU

    LaTeX AMSTeX: Vertical Line in Matrix

    Anyone know how to get a vertical line between two columns ? Like here in AMSTeX
  48. MrRobotoToo

    I Further Evidence of a 3.5 keV line in Galactic X-Ray Spectra

    That pesky 3.5 keV line just won't go away. The authors note that it's compatible with dark matter composed of 7.02 keV sterile neutrinos. If such is the case, the Majorana mass scale of the seesaw mechanism needn't coincide with the GUT scale (if such a scale even exists).
  49. M

    Prove the shortest distance between two points is a line

    Homework Statement Let γ : [0, L] → Rn be arclength parametrized. Show that the distance between the endpoints of the curve can at most be L, and equality can only hold when γ is a straight line segment. Thus, the shortest path between two points is the straight line segment connecting them...
  50. jlmccart03

    Find the magnitude of charge density for a power line

    Homework Statement The potential difference between the surface of a 2.2 cm -diameter power line and a point 1.9 m distant is 3.8 kV. What is the magnitude of the line charge density on the power line? Express your answer using two significant figures. Homework Equations V =...
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